Blowing arrangement for drills



Feb. 16, 1932. G. M. NEH. 1,845,806

BLOWING ARRANGEMENT FOR DRILLS Filed May 19, 1928 1 N VEN TOR.

A TTORNEY.

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Patented Feb. 16, 1932 GUSTAVE M. NELL, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. Y., A. CORPORATION OF NEW JERSEY BLOWING ARRANGEMENT FOR DRILLS Application filed May 19,

The present invention relates to percussive tools of the fluid pressure type for drilling holes in hard formations, and more particularly to tools of the above type c1 used with hollow drill. steels and clear the holes of dust and cur tings during the drilling operation.

One object of the invention is to provide simple and inexpensive means secured to the drill for closing or obstructing the exhaust ports of the drill at will so as to clear the drill. hole. Various other objects and advantages of the invention will be obvious from the following particular description oi orms of ap paratus embodying the invention and om an inspection of the accompanying drawings; and the invention. also consists in certain new and useful features of crmstruction and combination of parts hereinafter setforth and are . claimed.

In the a .:companying drawings there are shown for purposes of illustration one form of apparatus with certain modilicz of embodying the ii ention in n 1 Fig. 1 is a longitudinal sectional view in part of an air hammer having twin exhaust ports and removable plugs for these ports for diverting the exhaust to channels which will conduct it to the hollow drill;

Fig. 2 is a general view of a pair of plugs with a chain and holding spring connecting them; and

Fig. 3 is a view similar to that of Fig. 1 showing an alternate form which has a single exhaust port and corrrspomling single plug therefor.

In all the above described views of the drawings like characters of reference indicate corresponding parts.

The drawings showin part npcumatic drills adapted, upon closing of the exhaust ports, to blow air through a hollow d. 'll steel in a manner well known in the art, the invention relating particularly to a new arrangement of parts for closing the exhaust ports. In order to make clear the invention, it is unnecessary to describe the percussive motor in detail since the invention applicable to any type of percussive motor which utilizes main exhaust ports under the direct control of the hammer 1928. Serial No. 278,992.

piston. The particular form of drilling machine shown in, the accompanying drawings comprises a cylinder A in which reciprocates a hammer piston B delivering its blows upon a drill steel C, either directly or through an interposed anvil block (not shown), the steel being supported in the front head D which is secured to cylinder A by the usual thru bolts or side rods E which also clamp the backhead F to cylinder A. All portions of the machine in the central longitudinal axis of the same, including the rotation mechanism (if any), the piston and the drill steel, are provided with an axial bore directing cleansing fluid into the hole which is being drilled. In Fig. 1 a long water tube G extends axially through the parts of the drilling machine and into the upper end of the hollow drill steel as shown, this tube having a reduced portion to permit passage of the pressure fluid from the rear piston chamber of the drill around the tube when the piston is in its forward position as shown in Fig. 1.

The drilling mac shown in. Fig-'1 has formed in. the cylinder thereof at diametrically opposed points and under direct control of piston 1" two e: iaust ports 2, 2 opening for- '-'ardly and outwardly to atmosphere from a transverse plane substantially intermediate the extreme positions of the piston B in cylinder A. For closing said ports 2, 2 there is provided a pair of plugs l and 5 which are connected together by suitable flexible and resilient means, such as the chain 6 and tension spring 7. The chain 6 extends from plug 4 rcarwardly and over the baelrhead F of the cylinder, then forwardly to spring 7 which may be attached directly to plug 5. To prevent the plugs from being lost when not in use, but to permit free movement of the chain across bachhcad F, a retaining loop 8 of any suitable form and material is provided on backhcad F. The connection between the plugs is of such length that when the plugs are manually inserted in the exhaust ports 2, 2 of the machine, spring 7 is distended. and exerts a seating pressure on plugs a and 5 to retain them in ports 2, 2 as illustrated in Fig. 1. Plugs 4 and 5 are preferably provided with respective angular extensioi'ls 4a and 5a t ll to which the chain 6 and spring 7, respectively, are attached, and either or both of the extensions, such as 5a, may be of such length as to form a handle to facilitate the insertion and removal of the plugs. In Fig. 2 plugs 4 and 5 and their connecting chain 6 and tension spring 7 are shown laid out, the spring being in its normal contracted state.

The drilling machine shown in Fig. 3 is similar to the one shown in Fig. 1 except thatthe cylinder A has a single exhaust port 11 and is provided with a short blowing tube which is entirely withdrawn from the axial bore of piston B when the latter is in its forward position as illustrated, so that a portion of the exhaust pressure fluid from the rear piston chamber passes down through the piston and the drill steel when the piston delivers its blow. With this construction a single plug only is required to close the atmosphere exhaust port 11 when continuous blowing is required. Plug 12 has a handle extension 12a from which extends a flexible connection 13 which includes a tension or coil spring 14. The connection or chain 13 is attached to the backhead F of the machine by any suitable means, such as a rivet 15. In this form the plug 12 is pulled against the tension of spring 14 and then inserted into port 11 whereupon it is retained by spring 14 securely seated until manually withdrawn.

If desired the machine of F 1 with its two exhaust ports may have attached thereto a pair of the individual plugs and connections shown in Fig. 8 instead of the arrangem nt shown in Figs. 1 and 2.

lVhen the atmospheric exhaust ports of the machines shown in Figs. 1 and 3 are closed by the plug constructions herein illustrated, it will be obvious that the pistons'will be held in either their extreme forward or rearward positions because the pressure fluid which wa* available to move the piston is unable to escape immediately. With the piston trapped in its forward position, as shown, in Figs. 1 and 3, the trapped motive fluid will )ass around the reduced portion of water tube of Fig. l or into the unrestricted bore of the piston in Fig. 3. If the piston is held in its rearmost position, the pressure fluid trapped in the forward piston chamber will pass along the flutes of the piston extension and thence into the bore of the drill steel in an obvious manner. From the above, it will be apparent that the new port closure arrangement of the invention is economical, simple and of a construction having no parts to get out of order and is efl'ective to seat in and fully close the exhaust ports and to keep them closed.

lVhile preferred forms of the invention have been herein shown and described, it is to be understood that the invention is not limited to the specific details thereof, but covers all changes, modifications, and adaptations within the scope of the appended claims.

I claim as my invention:

1. The combination with a fluid pressure machine having a plurality of exhaust ports, of plugs arranged to fit in and to close each of said ports, and a flexible element securing said plugs together and to said machine and having a resilient portion acting equal- 1y upon both plugs yieldingly to maintain said plugs in said ports against the exhaust pressure.

2. The combination with a fluid pressure machine having a pair of exhaust ports, of a pair of plugs arranged to fit in said ports respectively to close the same, a flexible connection between said plugs including a resilient member, and means loosely securing said connection to said machine while permitting movement of the connection and free action of said member upon bothsaid plugs to retain them in said exhaust ports.

3. The combination with a fluid pressure machine having a pair of exhaust ports, of a pair of plugs arranged to fit in said ports respectively to close the sai e, a flexible connection between said plugs including a coil spring, anda loop member on the rearward portion of said machine through which said connection passes loosely to prevent separation of said plugs from said machine but to permit necessary relative movement of said plugs and free action of said spring on both said plugs for yieldingly retaining the latter in said exhaust ports.

1. Exhaust port closure means for fluid pressure tools having two exhaust ports comprising a flexible connecting element for attachment to the tool comprising a tension spring adapted to exert a contractive force along the length of said connecting element, and a pair of plugs of substantially uniform size throughout having bent portions forming handles, said connecting element having its ends secured to said handle portions of said plugs adjacent the bends therein.

Signed by me at Detroit, in the county of WVayne and State of Michigan, this 16 day or" May, 1928.

. GUSTAVE M. NELL. 

